Metacognition (knowing one's own mental states), and declarative cognition (expressing them) are essential cognitive functions and focuses of research. The proposed research will extend these research areas. It will give participants (human adults, children, nonhuman animals) a behavioral-report methodology by which they can describe their own task approach. It will give researchers a nonverbal way to instruct participants in the correct task approach. It will explore a new aspect of metacognition?the self-awareness of one's own task strategy. It will explore the roots of declarative cognition in young children, by providing a behavioral channel for self- report before the verbal channel fully supports that declaration. It will be transformative in comparative psychology, providing behavioral self-reports to animals for the first time. To this end, the proposed research asks whether participants can tune attention based on the instruction provided by abstract icons. It asks whether they can use those icons to make reports of their own task approach. It asks whether these icons can acquire quasi-symbolic properties, so that they are understood receptively (inducing instructional sets) and productively (allowing self-reports of task strategies). It addresses those questions using matching, categorization, same-different, and other influential tasks from comparative and developmental psychology. Finally, it asks whether participants can use their abstract icons to state their task preferences. Metacognition and declarative cognition are crucial to intellectual adaptation, educational success, and daily living. Understanding them well is an important scientific and mental-health goal. The proposed research will provide new ways to study the most basic forms of these capacities. It will provide animal models. These can be used in neuroscience studies to foster or rehabilitate these capacities. The research will give developmental researchers tools for exploring the beginnings of declarative cognition during child development. It will open nonverbal channels of declarative cognition that could serve humans impaired at verbal communication. These could support human comfort and palliative care. It will open a new metacognitive channel by which comparative psychologists may understand better animals' self-reflective minds.